Last week, the shadow Brexit secretary appeared on ITV’s flagship breakfast show Good Morning Britain. Sir Keir Starmer was there to face a grilling from presenters over his party's strategy for leaving the EU, as part of the daily merry-go-round of interviews in election season.

"I have been talking to the EU, to political leaders across the EU 27 countries, for three years and I know very well what the parameters are of any deal they would do with a Labour government," he said.

“We posted the full interview so people could see the full interview from which we derived that clip. Obviously our interview was light-hearted and satirical,” Cleverly told BBC Breakfast the next day.

This, too, was untrue. The main Conservatives account had retweeted a post from the party press office which showed part of Starmer’s interview without a jaunty soundtrack, but this ended before the question was put to him. The day passed and the news cycle moved on.

But the episode points to an emerging trend, from across the political spectrum, of invoking "satire" or "humour" as a justification for disinformation.

Worried that lies might deceive voters? Concerned about doctored videos of politicians circulating online? Well, comes the response, you should learn how to take a joke.

Three days after the Starmer video, on 8 November, another Twitter account repeated almost exactly the same trick. "News Addict", a pro-Conservative Twitter account with almost 13,000 followers, shared a video of BBC deputy political editor Nick Robinson interviewing Ian Blackford, the SNP leader in the House of Commons, on the day the party’s campaign launched. Similarly, the video had been edited to shorten or remove Blackford’s answers to questions about the NHS.

It has since been shared almost 4,000 times on Twitter, three times more than the Starmer video, and led to an embarrassing apology from Andrew Neil, the BBC’s political interviewing heavyweight, who shared the clip to his 950,000 followers.

To News Addict’s credit, the account did reply to anyone calling out the fakery by sharing the original, unedited interview. If anyone went further in asking why it had been edited so heavily, News Addict would repeatedly respond with a string of laughing emoji.

*The barriers to entry for reaching an audience of millions have plummeted and the social media platforms make it easier to propagate hoaxes than it is to check sources.*

The tactic is not limited to Conservatives, of course. On the same day as the Starmer interview took place, a tweet mocking Liberal Democrat leader Jo Swinson was posted by a fake BBC account. The account included BBC in the username and a stock image of a reporter holding a microphone and its tweet was shared more than 8,000 times before the account was suspended. A little digging would see the account was linked to a website with a satirical disclaimer, but this was not clear to anyone who saw the tweet in their feeds.

Nor is the tactic limited to the UK. The same has been seen around the world in recent elections as the barriers to entry for reaching an audience of millions have plummeted and the social media platforms make it easier to propagate hoaxes than it is to check sources.

In February, Brazilian agency Publico published an investigation into almost 100 Twitter accounts which had sprung into action during the bitterly fought election of President Jair Bolsonaro. With names like 'Gobo News' and 'Monica Bengamo' they were often difficult to distinguish at first glance from the real outlets and journalists they sought to ape, in this case Globo News and journalist Monica Bergamo. According to Publico, the accounts mixed real news and opinion in with the satire in a way one expert described as “intending to deceive” while pushing the same agenda which saw Jair Bolsonaro elected.

Then, in April, a Republican political operative created a fake campaign website for former US vice-president Joe Biden, one of the leading candidates to be the Democrat nominee for the 2020 election. The slickly produced site focuses heavily on Biden’s interactions with women and girls and opens with the line: "Uncle Joe is back and ready to take a hands-on approach to America’s problems!"

Satire is used strategically to bypass fact-checkers and to distribute rumours and conspiracies, knowing that any push back can be dismissed by stating that it was never meant to be taken seriously. – Claire Wardle, co-founder, First Draft

One of the most prominent examples comes from France. In 2017, as Emmanuel Macron was campaigning in the French presidential election, he was repeatedly met on the campaign trail by workers who challenged him to a handshake, believing he would turn them down. This belief was traced back to an article on satirical site Le Gorafi written almost a year earlier.

Adrien Senecat of LeMonde described the evolution of the rumour as part of the original CrossCheck project. Le Gorafi 'reported' that Macron would not shake hands with poor people, wrote Senecat, a report which was shared nearly 600,000 times on Facebook, including by many pages which supported his opponent, Marine Le Pen.

Other social media users then claimed a video in which Macron washed his hands came after a factory visit, spurring the falsehood on further. That clip came from a press event in which he handled a live eel.

This journey from a satirical article to real-life incidents took almost a year. But it was the active weaponisation of the joke which lit a rocket under a claim that had no basis in reality.

These historic examples are among those featured in a recently published book from First Draft by co-founder Claire Wardle titled 'Understanding Information Disorder', which looks at different types of mis- and disinformation.

"The reason that satire used in this way is so powerful a tool is that often the first people to see the satire often understand it as such," Wardle writes. "But as it gets re-shared more people lose the connection to the original messenger and fail to understand it as satire.

"On social media, the heuristics (the mental shortcuts we use to make sense of the world) are missing. Unlike in a newspaper where you understand what section of the paper you are looking at and see visual cues which show you’re in the opinion section or the cartoon section, this isn’t the case online."

The same goes for individual accounts themselves. The weekend before the Starmer video, a Twitter account posted screenshots of what appeared to be a story from the Daily Mirror about Liberal Democrat leader Jo Swinson. The story told an entirely fabricated tale of a video of Swinson found on her private Facebook page in which she used a slingshot to fire pebbles at squirrels. It has had nearly 1,000 retweets and nearly 3,000 likes. Dozens of Twitter users have referenced the baseless claim since.

One commenter replied: "[I don’t know] if it is indicative of how tired I already am [of] this general election that I really did feel the need to Google this, being 100 per cent unable to tell whether it could be true or not."

“The challenge in this age of information disorder is that satire is used strategically to bypass fact-checkers and to distribute rumours and conspiracies, knowing that any push back can be dismissed by stating that it was never meant to be taken seriously,” wrote Wardle.

Now, in 2019, it is not only random social media users, hyper-partisan supporters and extremists who are weaponising satire for political gains, but the very parties and candidates themselves. What effect this will have on the election remains to be seen.